Blade for flail-type mowing machines and the like

ABSTRACT

The blade is connected to the blade-mounting pin of the rotor by a link, which is a steel strip disposed in a plane parallel to the rotor axis, and having a U-type open loop at its outer end. The blade has a shank disposed in the link, two 90* side arms, and diagonal arm extensions. The extensions each have cutting edges facing both forwardly and rearwardly which cross each other to provide a combined cutting edge equal in width to the overall width of the blade member. The extensions are angularly offset to provide a clearance at the crossing point. The shank is maintained in the open loop of the link by a removable keeper pin and cotter pin which permits reversal of the blade to provide fresh cutting edges.

United States Patent Bernard C. Mathews Box 70, Crystal Lake, Ill. 60014[21] Appl. No. 12,095

[22] Filed Feb. 17, 1970 [45] Patented Jan. 11, 1972 [72] Inventor [54]BLADE FOR FLAIL-TYPE MOWING MACHINES [56] References Cited UNITED STATESPATENTS 2,509,343 5/1950 Henderson 56/294 3,159,957 12/I964 Mathews56/504 X Primary Examiner-Robert Peshock Assistant Examiner-J. A. OliffAttorneyZabel Baker York and Jones ABSTRACT: The blade is connected tothe blade-mounting pin of the rotor by a link, which is a steel stripdisposed in a plane parallel to the rotor axis, and having a U-type openloop at its outer end. The blade has a shank disposed in the link, two90 side arms, and diagonal arm extensions. The extensions each havecutting edges facing both forwardly and rear wardly which cross eachother to provide a combined cutting edge equal in width to the overallwidth of the blade member. The extensions are angularly offset toprovide a clearance at the crossing point. The shank is maintained inthe open loop of the link by a removable keeper pin and cotter pin whichpermits reversal of the blade to provide fresh cutting edges.

PATENIED JAN] 1 I972 INVENTOR BERNARD C. MATHEWS wfizw,

' ATT'YS.

BLADE FOR FLAIL-TYPE MOWING MACHINES AND THE LIKE This invention relatesto an improved blade and blade assembly for flail-type mowing machines,choppers and other flail-type forage harvesters.

It is an object of the present invention to provide a blade assembly inwhich the blade element itself is easily replaceable. In flail-typemowers, the cutting edge tends to get nicked due to hitting stones, withthe result that the individual blades have to be removed forresharpening, or replacement.

One of the main advantages of a flail-type mower is that a particularblade can swing back when a rock is engaged, and this does not interferetoo materially with the smooth action of the rotor as a whole. However,some blades are of quite heavy construction with the result that when arock is hit, there will be a certain amount of vibration, andfurthermore, the heavier the blade the greater the possible damage toit.

According to my invention, I provide a relatively lightweight blade, andthe blade assembly also includes a link, with the result that theinterference to the smooth rotating movement to the rotor is minimizedwhen the blade hits a rock because only the blade portion is displacedrearwardly.

Another object of my invention is to provide a blade assembly in whichthe articulations or hinges are of substantial length in the axialdirection so as to minimize the wear at the hinge point. For instance insome blade constructions, the blade element is a strip of metal, theplane of which at the hinge point is perpendicular to the axis of therotor. In other words, the strip has a hole punched in it and the holeis traversed by the link or other mounting pin. In this priorconstruction, all of the wear is concentrated along that edge of thehole which is engaged by the link or pin, and where the thickness of thestrip is from one-eighth to one-fourth of an inch, the metal wearsrather rapidly. In extreme instances, the hole or the link will wearthrough and the blade will fly off.

Accordingly to my invention the link element is a strip disposed in aplane which is parallel to the rotor axis, and the strip issubstantially 2 inches wide. Thus, a bearing surface 2 inches wide isprovided in which the wear is distributed over a much greater area ofmetal.

According to my invention, I provide a blade which includes crossedcutting edges, as well as a shank portion of a substantial length whichcooperates with the loop of the link. This has been found to provide asatisfactory combination of longwearing blade with lightweight togetherwith the other advantages above mentioned. Furthermore, my arrangementprovides a reversible blade so that when one cutting edge is worn thelife of the blade may be doubled by removing the blade, reversing andreplacing it.

In the drawings:

FIG. 1 is a sectional view of a flail-type mower embodying my invention;

FIG. 2 is a fragmentary section of the rotor showing the blade-mountingpins;

FIG. 3 is a front elevation of one of the blade assemblies shown in FIG.1;

FIG. 4 is a side elevation of FIG. 3 taken along the line 4-4 FIG. 3;

FIG. 5 is a plan section taken along lines 5-5 of FIGS. 3 and 4; and

FIG. 6 is a top plan view of the blade member alone.

The mower comprises a main frame 10 which includes side plates 11 whichare connected to each other by a top plate 12 and a crossbar 13. Atransverse tubular member 14 connects the main frame 10 to a drawbarassembly, not shown. The details of the mower are fully described in myUS. Pat. Nos. 3,159,957 and 3,l59,959 granted Dec. 8, 1964.

The side plates 11 support a rotor 15 which is driven in the directionof the arrow by suitable means. A front wall 16, which may be hingedlymounted on the top plate 12, encloses the upper forward portion of therotor 15. A plant deflector in the form of a roller 17 may be carried atthe lower end of the front wall 16. The mower as a whole is partiallysupported by wheels, of which one wheel 18 is shown, and is partiallysupported from the tractor by the usual draw bar assembly.

The rotor 15 comprises a tubular member 20 shown in FIG. 2 having anumber of pins 21 arranged parallel to the rotor axis upon which theblade assemblies may be mounted. The pins 21 may be mounted in spacedrelation to the tubular member by any suitable brackets, such as theplates 22 shown in FIG. 2.

The blade assembly 23 shown in FIGS. 3 and 4 comprises a link 24 and ablade member 27. The link 24 is a steel strip with its plane arrangedparallel to the axis of the rotor 15 and elements 20 and 21. The link 24has a closed loop 25 at its upper end which surrounds the blade mountingpin 21 and provides a hinged joint. The lower end of the link 24comprises a U- type open loop 26. The blade member 27 comprises at itsupper portion a C-shaped structure comprising a horizontal shank 28 andside arms 29 and 30 arranged at substantially to the shank. The sidearms and the shank are of circular cross section, and the shank isreceived within the open loop 26 and secured therein by a keeper pin 36and a cotter pin 37. The pin 36 passes through aligned holes in theopposite sides of the open loop 26.

The side arms 29 and 30 have diagonally disposed extensions 31 and 32.The plane of elements 29-31 diverges outwardly from the plane ofelements 30-32 so that the extensions 31 and 32 may cross each other,providing a clearance 35 therebetween. The outer portions of thediagonal extensions 31 and 32 are each shaped to provide a forwardlyfacing cutting edge 33, and a rearwardly facing cutting edge 34. Thelength of the extensions is such that the end 310 of extension 31 isextended laterally to a point substantially even with the extremeright-hand surface of the side arm 30. The end 320 of extension 32extends to a point about even with the extreme left-hand surface of theside arm 29. Thus the two crossed and overlapping blade portions 31 and32 provide a combined cutting edge which is substantially equal to theoverall width of the blade member 27 at its widest portion, the width ofthe swath being cut by the combined blade portions being indicated bythe letter S in FIG. 6.

The swath S is therefore wider that the link 24. The pins 21 arepreferably staggered so that axially adjacent pins are angularly offsetfrom each other. Thus the swath S cut by one blade member will overlapthe swath cut by an axially adjacent but angularly offset blade member.

The blade member 27 is made from a high carbon steel, and the cuttingedges 33 and 34 are forged on to the rod stock blank. Then the blank isbent into the final shape and heattreated.

The link 24 is made of similar high-carbon strip steel stock, and thenformed and heat-treated.

The blade-mounting pins 21 can be in the form of threaded nuts and boltsof suitable high-carbon heat-treated steel, and the nuts 38 are tackedwelded to the bolts 21 after tightening.

The clearance 35 is of the order of from one-fourth to threeeighthsinch. Without the clearance, the grass tends to catch on the blade atthe point of intersection, with the result that a mass of grass buildsup with continued revolutions. The clearance or gap 35 permits the grassto fly outwardly, off of the blade portions 31 and 32, which aredisposed about 45 to the horizontal.

In spite of the clearance 35, the blade member 27 cannot becomedislodged from the link 24 because the location of the keeper pin 36 issufficiently close to the shank 28 as to prevent a canting andsubsequent inversion the blade member 27.

The present construction avoids any split-ring blade construction inwhich the very substantial centrifugal forces involved tend to open upthe ring at the split.

When the cutting edges 33 become worn or nicked, withdrawal of thekeeper pin 36 permits the blade member 27 to be reversed so that thefresh edges 34 are presented for mowing, thus the life of the blademember 27. Substitution of a new blade is similarly accomplished withease.

What is claimed is:

l. A blade for the rotor of a flail-type mowing machine, said rotorhaving a blade-supporting link, said blade comprising a shank and twoside arms, said side arms each including a diagonally disposedextension, said extensions being angularly offset from each other withrespect to the longitudinal axis of said shank and crossing each other,and said extensions each having a forwardly and a rearwardly facingsurface, each of said forwardly facing surfaces having a forwardlyfacing cutting edge therealong the angular offset of said extensionsproviding a clearance between the forwardly facing edge of one extensionand the rearwardly facing surface of the other extension at the point ofcrossing.

2. A blade as claimed in claim 1 in which said extensions are also eachprovided with a rearwardly facing cutting edge along said rearwardlyfacing surface.

3. A blade assembly for the rotor of a flail-type mowing machine, saidrotor having blade-mounting pins, said blade assembly comprising a linkhaving means at one end for hingedly mounting same on one of saidblade-mounting pins and having loop means at the other end, a blademember having a shank and two side arms, said shank being received insaid loop means with its longitudinal axis parallel to the longitudinalaxis of said rotor, said side arms each including a diagonally disposedextension, said extensions being angularly offset from each other withrespect to said longitudinal axis of said shank and crossing each other,and said extensions each having a forwardly and a rearwardly facingsurface, each of said forwardly facing surfaces having a forwardlyfacing cutting edge therealong.

4. A blade assembly as claimed in claim 3 in which said link is a steelstrip disposed in a plane parallel to the longitudinal axis of saidrotor.

5. A blade assembly as claimed in claim 4 in which said loop means is anopen loop, and means for removably securing said shank in said openloop.

6. A blade assembly as claimed in claim 3 in which the angular offsetbetween said extensions is of an extend sufficient to provide aclearance between the forwardly facing edge of one extension and therearwardly facing surface of said other extension.

7. A blade assembly as claimed in claim 3 in which each extensionterminates at a point substantially even with the extreme side surfaceof the side arm associated with the other extension so that the swathcut by said two forwardly facing edges is of a width substantially equalto the over all width of said blade member.

8. A blade as claimed in claim 3 in which said extensions are also eachprovided with a rearwardly facing cutting edge, along said rearwardlyfacing surface and means for removably securing said shank in said loopmeans to permit reversal of said blade member.

9. A blade assembly for the rotor of a flail-type moving machine, saidrotor having blade mounting pins disposed parallel to the longitudinalrotor axis, said blade assembly comprising a link including a steelstrip of substantial width hingedly mounted at one end of one of saidblade-mounting pins and having an open loop at the other end, a blademember having a shank and two side arms providing a C- shaped portion,said shank being received in said open loop with its longitudinal axisparallel to the longitudinal axis of said rotor, said side arms eachhaving a diagonally disposed extension, said extensions being angularlyoffset from each other with respect to said longitudinal axis of saidshank and crossing each other, said extensions each being provided witha forwardly facing cutting edge and a rearwardly facing cutting edge,the ends of each extension terminating at a point substantially evenwith the extreme side surfaces of said side arms so that the swath cutby said two forwardly facing edges is substantially equal to the widthof said C-shaped portion, the angular offset of said extensionsproviding a clearance between the forwardly facing edge of one extensionand the rearward facing edge of the other extension, and means forremovabl securing said shank i n said open loo 10. A lade assembly asclaimed in claim in WhlCh said removable securing means comprises akeeper pin extending through said open loop above said shank.

11. A blade assembly as claimed in claim 10 in which said open loop is aU-type open loop having aligned apertures in the opposite walls thereof,said keeper pin extending through said apertures, and a cotter pin forretaining said keeper pin in place.

1. A blade for the rotor of a flail-type mowing machine, said rotorhaving a blade-supporting link, said blade comprising a shank and twoside arms, said side arms each including a diagonally disposedextension, said extensions being angularly offset from each other withrespect to the longitudinal axis of said shank and crossing each other,and said extensions each having a forwardly and a rearwardly facingsurface, each of said forwardly facing surfaces having a forwardlyfacing cutting edge therealong the angular offset of said extensionsproviding a clearance between the forwardly facing edge of one extensionand the rearwardly facing surface of the other extension at the point ofcrossing.
 2. A blade as claimed in claim 1 in which said extensions arealso each provided with a rearwardly facing cutting edge along saidrearwardly facing surface.
 3. A blade assembly for the rotor of aflail-type mowing machine, said rotor having blade-mounting pins, saidblade assembly comprising a link having means at one end for hingedlymounting same on one of said blade-mounting pins and having loop meansat the other end, a blade member having a shank and two side arms, saidshank being received in said loop means with its longitudinal axisparallel to the longitudinal axis of said rotor, said side arms eachincluding a diagonally disposed extension, said extensions beingangularly offset from each other with respect to said longitudinal axisof said shank and crossing each other, and said extensions each having aforwardly and a rearwardly facing surface, each of said forwardly facingsurfaces having a forwardly facing cutting edge therealong.
 4. A bladeassembly as claimed in claim 3 in which said link is a steel stripdisposed in a plane parallel to the longitudinal axis of said rotor. 5.A blade assembly as claimed in claim 4 in which said loop means is anopen loop, and means for removably securing said shank in said openloop.
 6. A blade assembly as claimed in claim 3 in which the angularoffset between said extensions is of an extend sufficient to provide aclearance between the forwardly facing edge of one extension and therearwardly facing surface of said other extension.
 7. A blade assemblyas claimed in claim 3 in which each extension terminates at a pointsubstantially even with the extreme side surface of the side armassociated with the other extension so that the swath cut by said twoforwardly facing edges is of a width substantially equal to the over allwidth of said blade member.
 8. A blade as claimed in claim 3 in whichsaid extensions are also each provided with a rearwardly facing cuttingedge, along said rearwardly facing surface and means for removablysecuring said shank in said loop means to permit reversal of said blademember.
 9. A blade assembly for the rotor of a flail-type movingmachine, said rotor having blade mounting pins disposed parallel to thelongitudinal rotor axis, said blade assembly comprising a link includinga steel strip of substantial width hingedly mounted at one end of one ofsaid blade-mounting pins and having an open loop at the other end, ablade member having a shank and two side arms providing a C-shapedportion, said shank being received in said open loop with itslongitudinal axis parallel to the longitudinal axis of said rotor, saidside arms each having a diagonally disposed extension, said extensionsbeing angularly offset from each other with respect to said longitudinalaxis of said shank and crossing each other, said extensions each beingprovided with a forwardly facing cutting edge and a rearwardly facingcutting edge, the ends of each extension terminating at a pointsubstantially even with the extreme side surfaces of said side arms sothat the swath cut by said two forwardly facing edges is substantiallyequal to the width of said C-shaped portion, the angular offset of saidextensions providing a clearance between the forwardly facing edge ofone extension and the rearward facing edge of the other extension, andmeans for removably securing said shank in said open loop.
 10. A bladeassembly as claimed in claim 9 in which said removable securing meanscomprises a keeper pin extending through said open loop above saidshank.
 11. A blade assembly as claimed in claim 10 in which said openloop is a U-type open loop having aligned apertures in the oppositewalls thereof, said keeper pin extending through said apertures, and acotter pin for retaining said keeper pin in place.